Controlling gas turbine engine blade tip clearance is desirable so as to maintain engine structural integrity and efficient performance. Turbine efficiency improves as the clearance or gap between turbine blade tips and a surrounding static structure is reduced. The static structure comprises a blade ring coupled to an engine casing and a ring segment coupled to the blade ring via isolation rings. The ring segment is exposed to hot working gases passing through the gas turbine. During engine startup, the turbine blades radially expand quickly due to a rapid increase in the temperature of the hot working gases impinging and centrifugal forces acting on the blades. Also during start-up, the blade ring expands radially outward away from the blade tips as the temperature of the blade ring increases. However, the temperature of the blade ring increases to its steady state temperature at a slower rate than that of the blades during engine start-up. The diameter of the blade ring and the length of the blades are designed so that during engine startup, the tips of the blades do not contact an inner surface of the static structure ring segment. However, during steady-state operation, the gap between the blade tips and the static structure ring segment increases due to the blade ring temperature increasing.